# Tag Info

## New answers tagged popular-science

11

Method 1: Foucault Pendulum As user Rob asks, what is wrong with a short Foucault pendulum? There is a problem, but it can be overcome inexpensively, but with some DIY effort at home. The problem is that, by dint of imperfections in the suspending fibre and bob, no pendulum will swing in a plane even if the Earth were not rotating. Instead, the bob will ...

2

To escape Earth, you'd need to be alive for (see this) $$\frac{1}{365 E} \left(\frac{GMm}{R}\right) \ \mbox{years} \approx 1 \ \mbox{year},$$ where $E \approx 2000 \times 1000 \times 4 \ J = 8 \times 10^6 \ J$ is the average daily energy intake (couldn't find a good source for a worldwide average), $G \approx 7 \times 10^{-11} \ m^3 kg^{-1} s^{-2}$ is the ...

3

Some quick scribbling suggests that caloric intake for a $70\;{\rm kg}$ human over the course of $50\;{\rm yr}$ at $2500\;{\rm Cal}$ per day is enough to accelerate that person to almost $75,000\;{\rm m}/{\rm s}$. Escape velocity from Earth is about $11,000\;{\rm m}/{\rm s}$, so even with a reasonable hit for inefficiency (about $2\%$ energy efficiency is ...

0

I would tell her the bubbles contain water, and that water is sticky. I would remind her that even after she lets water run off her hands by gravity, she still needs to dry them off with a towel (unless you use an electric hand dryer), because some of the water sticks. It's easier to see the foam than it is to see the water, because the foam is puffed up ...

0

Your question is most right. But if we live in a 3d world not just a sheet because a sheet as you would say it has a bottom but what about the 3d vision of it don't you think it has a top and bottom and sides, just take a round ball and wrap a sheet around it add gravity to it and we really don't have a sheet but that only a visual complex of ones ...

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